Sugars substituted at the anomeric position by a hydroxyl group (1--OH) are important intermediates in the synthesis of active pharmaceuticals. These include for example, intermediates useful in the synthesis of anticancer glycosides such as etopside and teniposide; anticancer aminoglycosides of the anthracycline family such as daunorubicin; and glucuronides possessing various biological activities, including treatment of malignant tumors (K. A. Watanabe, et al, J. Med. Chem., 24, 893 (1981); M. Kaneko et al., Chem. Pharm. Bull., 25, 2458 (1977): Europ. Pat. Appl. No. 82793). In addition compounds of Formula IV have been used in the preparation of glycosides and oligosaccharides, either as such, (N. Morishima, S. Koto, Chem. Lett., 1039 (1982)), or after being transformed into a more reactive moiety (R. R. Schmidt, M. Hoffman, Tetrahedron Lett., 23, 409 (1982)). The reported preparation of 1--OH sugars has involved heavy metal, primarily silver salt (silver oxide or silver carbonate) catalyzed solvolysis of 1-bromo sugars, (Org. Syn. Coll. Vol. 3, p 434; D. Keglevic, Adv. Carbohydr. Chem. Biochem., 36, 57 (1979)). This procedure, in addition of using expensive metal reagents, suffers also from the instability of the starting 1-halo derivatives which readily decompose even below room temperature.
Recently a procedure for the preparation of 1--OH and 1--OH-2-amino sugars derivatives was described, (Japanese Kokai: Tokkyo Koho J5 58, 144, 396), in which polyacetylated and 2-N-tosyl and 2-N-acetyl-polyacetylated sugars were treated with bis-tri-n-butyltin oxide in refluxing toluene for four hours to afford 65% of the corresponding 1--OH derivates. However, this process is cumbersome and inconvenient in its workup, since the side product of the reaction, which is tri-n-butyltin acetate, is difficult to remove from the reaction mixture and may contaminate the final product. Moreover this side product constitutes a waste of 50% of active tin reagent.